What is the name of spruce undergrowth? Search results for \"spruce undergrowth\"
This word is “puppeteer”, which is explained quite simply. Everything connected with the word “doll” is associated with something small associated with the younger generation, so a word has been chosen for “children.”
A little information about the “teenager”:
The word "teenager" itself denotes a generation young trees that have grown either in the forest itself under the canopy of older trees, or in an empty place - these can be cut down or burnt areas.
Based on their age, undergrowth trees are classified as young trees.
The practical significance of “undergrowth” is quite significant: it is areas with young trees that can become the basis of a new forest area.
People have long understood the importance of such “undergrowth” for the conservation of forests. Therefore, in addition to natural areas with young trees, you can also find artificial ones, that is, specially planted ones; more often, combined ones are found. Experts evaluate the quality indicators, species, density of existing natural regrowth in terms of the number of trees per certain unit of area and plant new specimens, bringing the density of plantings to the established optimal norm and thereby laying the foundation for new tiers of the forest.
In addition to monitoring undergrowth, forestry specialists use a number of practical measures to promote the proper formation of the forest, for example, various types of felling, which have their own purpose and specificity.
Undergrowth can be used for reforestation of cleared areas in many cases with very great effect. The use of spruce, cedar and fir undergrowth is especially important, since the subsequent regeneration of forest stands of these species is associated with great difficulties due to the very slow growth of undergrowth in the first years of its life.[...]
In many cases, spruce undergrowth recovers from felling much more slowly than pine (Fig. 36). In the first 2-3 years, growth decreases or increases slightly. In subsequent years, the growth increases noticeably, especially in green moss forests (better in pine forests, somewhat worse in spruce forests).[...]
Pine undergrowth is a source of seeding of a narrower geographical and forest typological range compared to spruce. Nevertheless, it is also an important source of seeds for some areas and types of forest. In the northern taiga regions, pine trees begin to bear fruit early. In concentrated clearings of the Kola Peninsula, fruit-bearing undergrowth and even pine seedlings are found. Under the same conditions, in 25-35 year old pine trees on lichen and shrub-lichen clearings, up to 50% of trees or more bear fruit in productive years.[...]
Thus, undergrowth for concentrated felling not only itself is the basis of the future forest stand as a preliminary renewal, but under certain conditions serves as one of important sources seeding of these fellings.[...]
The occurrence of undergrowth’ was chosen as one of the most important criteria for silvicultural and environmental requirements for the operation of logging machines during clear-cutting. Occurrence is a reliable indicator for assessing natural forest regeneration (Martynov, 1992; Tikhonov, 1979), allowing one to predict the composition and productivity of future forest stands. The occurrence indicator can also be successfully used to predict subsequent forest regeneration based on the nature of forest growth conditions in fresh felled areas and the possible formation of one or another type of clearing or its fragments (parcels). The value of this indicator depends on forest conditions, biology and ecology of tree species.[...]
The use of undergrowth is of great importance for the regeneration of oak, beech, hornbeam, and linden forests. For satisfactory and good renewal, the old undergrowth of these species, which takes on a bushy creeping form, should be planted on a stump, that is, cut down leaving a small stump, on which shoots then appear (“sit down”) from dormant buds, characterized by more slender growth than felled old undergrowth. Planting on a stump is also quite advisable for old undergrowth of elm, maple, chestnut and other species.[...]
For example, the amount of spruce undergrowth under the mother canopy per unit area naturally changes within the range of this species: it decreases to the north and south of the areas optimal for spruce growth. The southern border of these regions extends further to the south in the western, more humid part of the European territory of the USSR, and shifts somewhat to the north in the eastern, more continental (meaning flat areas). In the sparse and northern subzones of the taiga, the amount of spruce undergrowth per unit area is less than in the southern subzone, but at the same time, spruce grows here in a wide typological range; it even enters lichen forest types. It is necessary to take into account the comparative potential productivity of undergrowth of different tree species growing in the same area in order to place the main emphasis on the species that, under given physical and geographical conditions, is capable of forming the most highly productive forest stands. Thus, in the mentioned forests of lichen types, as well as in northern lingonberries, the productivity of spruce stands significantly lags behind pine ones. A unique feature of spruce regeneration in a number of areas of the European taiga is also its ability to appear as a pioneer in burnt areas and clear-cuts under certain soil and microclimatic conditions; this phenomenon was noted and described by the author in the late twenties and early thirties.[...]
Thus, the preservation of undergrowth is an important type of regulated natural regeneration. At the same time, it cannot be considered as the only way of natural regeneration during clear-cutting. So, for example, it is not advisable to rely on spruce undergrowth growing under the pine canopy on poor soils, where the productivity of the pine stand is much higher than that of spruce.[...]
The number of cones and seeds in young spruce and pine trees is less than in most adult trees. However, this is compensated by a large number of undergrowth plants and a possible improvement in seed quality. The most valuable is the undergrowth that grows before felling in windows and generally under the sparse forest canopy, since its fruiting may occur earlier during clearing. Such undergrowth sometimes bears fruit even before felling.[...]
Due to the fact that the preserved spruce undergrowth (20 years old at the time of felling) will subsequently occupy the first tier in the canopy of the emerging young growth, the need for thinning practically disappears. According to A. S. Tikhonov, spruce, growing from 15-20-year-old undergrowth, at the age of 70 years has the same height as birch and aspen. Thinning is necessary only in places with a predominance of small undergrowth preserved (during logging) and spruce undergrowth that is subsequently renewed. Within 10 years, the type of felling under consideration is transformed into the initial stage of the forest type - mixed-grass spruce forest (hereinafter - fresh blueberry).[...]
The growth of undergrowth in peaty sphagnum pine forests changes relatively little, which is associated with small changes in the light regime after felling and with unfavorable soil conditions.[...]
An external sign of the viability of a young tree can be its growth in height. With an average annual growth rate of 5 aa or more over the past 5 years, spruce and fir regrowth 0.5-1.5 m high can be considered quite viable, able to withstand sudden lightening of its upper canopy by clear cutting. [...]
The quality of forest stands formed from the undergrowth of preliminary generations is closely related to the nature of its damage during logging. Places of mechanical damage to spruce undergrowth are often affected by rot, which leads to a decrease in the quality of the wood. Spruce wood is affected by rot when the width of the wounds around the circumference of the undergrowth trunk is 3 cm or more. These wounds do not heal for a very long time, sometimes throughout the entire life of the trees. Smaller wounds heal within 15 to 20 years. Rot, formed as a result of wounds of the first kind, covers about 3 m of the butt part of the trunk over 60 - 70 years.[...]
It is much more difficult to preserve undergrowth in mountain forests than in lowland forests. A lot of undergrowth there is destroyed by unsystematic ground skidding by self-raising. Ground skidding with winches and tractors also causes more damage to undergrowth than in lowland forests. The steeper the slopes, the more undergrowth is damaged.[...]
In the forests of the taiga zone there is often large number undergrowth, which is due to the high age and therefore the relatively low completeness of tree stands. The appearance of undergrowth under the canopy was also facilitated by ground-level runaway fires, which caused thinning of tree stands and damage to the ground cover (I.S. Melekhov, A.A. Molchanov, etc.).[...]
Sometimes, after felling, frail, although viable, spruce undergrowth remains, characterized by slow growth. Such undergrowth can only form a tree stand of low productivity. The reason for this is not only the suppression of undergrowth under the canopy and the reaction to lightening, but also soil conditions. It is advisable to replace such undergrowth by first preparing the soil by fire or some other method for subsequent artificial regeneration, for example, of pine, if this turns out to be cost-effective and leads to the formation of forest stands of more high productivity.[ ...]
Let's take, for example, two areas: in one there is evenly distributed coniferous undergrowth, in the other there is no undergrowth. In the first case, you can leave several insurance seeds per 1 hectare, in the other - more to ensure complete seeding of the entire plot.[...]
The study showed that the intensity of respiration of the conducting roots of spruce undergrowth, both in terms of the mass of CO2 released and the amount of absorbed O2, is higher in the clearing than under the forest canopy (Table 1). During the study period, respiration energy is subject to quite significant fluctuations, and from the second half of July there is a noticeable rise in the respiration curve associated with changes in both ambient temperature and soil moisture (Table 2). However, the increase in respiration intensity does not correspond to the temperature coefficient [...]
In economic practice, it is necessary to take into account and study not only the existing undergrowth under the forest canopy, but also... deforestation, burning, etc., but also the conditions for its appearance and development. An integral part of the issues of accounting and research of forest regeneration is the scientific and practical study the fruiting of the forest, like necessary condition seed reforestation, natural and artificial.[...]
When visiting the Buzuluksky forest, another thing that catches your eye is the presence of viable pine undergrowth under the sparse forest canopy, usually in windows. This characteristic phenomenon prompted G.F. Morozov and other foresters on the idea of using group selective felling. This idea was practically implemented later, and in the form not of group-selective felling, but of simplified, group-gradual felling. For the first time, group-gradual logging in the Buzuluksky pine forest was carried out in 1928 on an experimental basis, and in 1930 on a production scale. These fellings were carried out in four stages (Table 11) in mossy pine forests on more or less dry sandy soils.[ ...]
The Kostroma method gives good results if the young growth consists of self-seeding and small undergrowth up to 0.5 m high. In this case, up to 50-60% of it is preserved. If large undergrowth predominates, the damage rate is higher, and in this respect the Kostroma method is inferior, for example, to the methods used in some forestry enterprises in the Arkhangelsk region and Karelia, which allow preserving up to 70% of large and small undergrowth. The use of support trees is not always effective, and not only because of the height of the undergrowth. In low-productive thin-sized tree stands, they do not save even small undergrowth from damage during felling, so it is advisable to use them in highly productive forests.[...]
In these cases, almost more often the problem is to achieve the proper participation of coniferous undergrowth in the composition of the forest, since usually clear-cut areas here, as already indicated, are perfectly populated by birch, aspen, and alder, unless there is some admixture of them in the felled forest. [...]
During forced selective felling, it is not uncommon for growing trees to be damaged during felling and the undergrowth or felling of one tree when it hangs causes the need to cut down neighboring trees and the loss of the tree stand.[...]
In taiga clearings, according to V. Ya. Shiperovich, B. P. Yakovlev, A. A. Panov and others, the roots of coniferous undergrowth damage the root veins. As studies of recent years have shown (V. Ya-Shiperovich, B. P. Yakovlev, E. V. Titova), in Karelia the most common and harmful rootworms are Siberian (Hylastes aterrimus Egg.) and spruce (Hylastes cimicularius Egg.). They cause damage mainly in the process of additional feeding, attacking healthy undergrowth and young spruce and pine trees. The greatest harm from them can occur in three- to five-year-old felling areas. According to E.V. Titova, in four- to six-year-old fellings, the number of young fir trees damaged by spruce roots reaches 90%, about 20% dry out completely.[...]
Finally, if viable young growth is preserved in sufficient quantities (2000-3000 pieces of coniferous undergrowth per 1 hectare), there is no need for artificial reforestation, which is expensive. [...]
Thinning in the first years of life of young animals, called lightening, consists of freeing the undergrowth of valuable species from being drowned out by minor impurities, regulating the relationships between specimens of undergrowth of the same tree species, and improving conditions for the growth of the best specimens of valuable species. The first round of thinning for undergrowth can be carried out before the introduction of the main species into the area, an example of which is cutting corridors among elm, maple, linden, and hazel to introduce oak using the Molchanov method.[...]
Seed groups, clumps, stripes. Using materials about the composition and structure of the forest stand, the placement of undergrowth and undergrowth, and places of possible undercuts, it is possible to pre-designate intra-cutting seed clumps and seed groups for abandonment. The area of the seed group usually occupies 0.01, less often 0.03 - 0.05 hectares. The area of the curtain reaches several tenths of a hectare, and sometimes reaches 1 hectare. In this regard, the danger of decay from the wind is greater for the seed group than for the clump. The seed group is a compact biogroup, which includes several ripening or ripe trees or undergrowth and thin trees.[...]
Pine is especially hard hit by snowbreakers, and aspen is the hardest hit among deciduous trees. Heaps of snow often damage young growth in forests and clearings. A measure to prevent snow breaker and snowfall is the timely thinning of excessively dense tree stands, the creation of forest forms with a loose crown canopy.[...]
The main condition for successful regeneration of spruce during selective felling is the preservation of self-seeding and undergrowth during felling and skidding of trees.[...]
After felling (in a wet blueberry spruce forest) using a technology that ensures a fairly high preservation of the undergrowth (50-60%), the formation of the sphagnum type of felling has a certain influence on the preliminary regeneration of the spruce. Thus, in 6-year-old fellings of this type (after the operation of the LP-19, LT-157 and Timbergek-360 machines) on an intact soil surface with preserved spruce regrowth (9.6 thousand pieces/ha, average age 18 years) The projective cover of herbaceous and shrub vegetation is 35-45%. The cover is dominated by sedge (15-20%) and blueberry (4-5%). Sphagnum moss occupies 20-30%, and green mosses - 5-7% of the area. In biogroups of spruce undergrowth, the cover of herbaceous and shrub cover is reduced to 15%. Here the participation of blueberries increases (up to 6-8%), green mosses (up to 15-20%) and the area occupied by sphagnum moss decreases (up to 15-20%). This regrowth has a positive effect on the subsequent regeneration of spruce. Consequently, the spruce undergrowth preserved during felling, which is a natural drainer, promotes the subsequent regeneration of spruce and somewhat inhibits the formation of sphagnum type felling. In the taiga forests of the European part of the USSR, the nature of sphagnum and sedge-sphagnum fellings and the regeneration of forests on them (formed after the work of traditional logging equipment) were studied by many researchers.[...]
In high-density (0.8 and above) spruce-deciduous, deciduous-spruce and deciduous stands with self-seeding and undergrowth of spruce, it is justified to carry out gradual felling in three stages with an intensity of initial reception from 25 - 30%, stock (in spruce-deciduous) - up to 35 - 45% (in deciduous-spruce and deciduous), in medium-density forest stands, cutting in two steps is advisable.[...]
It is more difficult to formalize the silvicultural and environmental assessment of the operation of logging equipment in cutting areas without undergrowth than in plantations with undergrowth. The complexity of solving this problem lies in the fact that we are dealing not with the real (before cutting), but with the future (subsequent) regeneration of the forest, which immediately after cutting is predicted with a certain reliability, based on the state of forest conditions in fragments of fresh fellings and emerging ones. on them parcels of plant communities in the presence of seed sources. Therefore, for an objective assessment of the operation of logging equipment, scientific data is needed for different ecological and geographical conditions on the nature of damage to the soil cover in connection with the use of one or another type of machines and technologies, on the nature of the emergence and development of parcels and types of fellings, on their impact on the emergence of seedlings and formation of self-seeding and undergrowth. Such data is available for a number of regions. Below is an assessment of the performance of aggregate logging equipment in clear-cutting in two different regions based on soil and climatic conditions. Thus, in the conditions of a lingonberry-ledum pine forest (Tyumen region) and a fresh blueberry spruce forest (Novgorod region) after the operation of LP-19 and LT-157 machines using a technology that involves laying trees at an angle to the drag, causing approximately the same area of soil damage (80-85%), the same reed-reed type of felling is formed with different forest conditions in each region. The duration of existence and features of the formation of this type in the two regions are not the same (Obydennikov, 1996). The occurrence of fragments of clearings with favorable conditions for the regeneration of the main species is, in the first case, in the conditions of a lingonberry-ledum pine forest, 72-77% (Tyumen region), in the second, in the conditions of a fresh blueberry spruce forest, 4-8% (Novgorod region). The given indicators, judging by the results of the studies, correspond to the actual occurrence of undergrowth of subsequent renewal in the presence of testes.[...]
To ensure good reforestation, appropriate care of valuable, economically important undergrowth is necessary - weeding and cutting down undergrowth and undergrowth of low-value species. Ignoring these measures was one of the main reasons for the unsuccessful use of gradual logging in pre-revolutionary Russia. Forest owners or officials usually tried to get forest regeneration without any significant financial costs, often relying only on regulation of the procedure for cutting down forests. Therefore, for example, as a result of ten years of experience in using gradual felling in the Sarapul district of forests of the Specific Department, according to a special survey by Danilevsky, it turned out that the vast majority of cutting areas in pine forests resumed unsatisfactorily and only 10-20% of all fellings resumed well. A survey of gradual cutting sites in the spruce forests of the Lisinsky forestry, carried out by D. M. Kravchinsky, showed that without caring for undergrowth, the regeneration of spruce turned out to be almost the same as in clear cuttings, namely, with the dominance of deciduous species (with a change of species) , against which the gradual felling was directed. D. M. Kravchinsky himself noted that in high-productivity spruce forests, the regeneration of spruce during gradual felling is hampered by the development of cereals (mainly reed grass) and undergrowth (mainly mountain ash) in the cutting area. [...]
In the lichen forests of the Arkhangelsk region, under the canopy, there are large numbers of strongly suppressed (sticky) pine undergrowth, which, after felling, quickly adapts to new conditions. Already 6-8 years after felling, such undergrowth differs little from pine trees that grew in the clearing. Only on the pre-cutting part of the stem are many young branches formed (from dormant axillary buds) (Fig. 15). Small-growing, strongly oppressed, the undergrowth is well preserved (84%) from damage during winter logging - even on portages with a single passage of the TDT-40 tractor in the summer, viable specimens of the undergrowth were preserved (Listov, 1986).[...]
Foresters were not satisfied with the relationship of tree species to light, established by the density of foliage and the nature of the crown, by the speed at which trunks are cleared of branches and by the ability of undergrowth species to survive under the shade of the upper tiers of tree stands. They tried to move experimentally to the quantitative expression of the degree of light-loving and shade-tolerance using other methods.[...]
The regeneration of pine in concentrated fellings depends on the time elapsed after the fire (Fig. 16). As the age of the fire increases to 20 - 25 years, the amount of self-seeding and regrowth of pine increases sharply. In areas where there was a fire 30 - 40 years ago, the amount of self-seeding and undergrowth decreases as a result of the transition of part of it to the polewood stage, but still remains significant. Restoration is also proceeding successfully in areas with a longer fire duration (up to 40 - 60 years), although the amount of self-seeding and undergrowth continues to decrease. In areas where there were no fires or where they occurred more than 100 years ago, pine regeneration is usually less successful.[...]
Wide Application at a number of enterprises Western Siberia(in particular, at the Komsomolsky and Sovetsky lumber mills in the Tyumen region) a technological scheme was found that preserves undergrowth (when installing two timber hauling mustaches, Fig. 31). According to the scheme, the LP-19 feller-buncher and chokerless skidders (LT-157, LT-154, etc.) are used. Before cutting the forest, two logging trucks and two loading platforms are installed at opposite ends of the cutting area. The LP-19 machine produces forest felling in strips (the width of each strip is 15 - 16 m).[...]
Thus, silvicultural requirements for technological processes during logging, it is customary to establish by the direct impact of logging equipment on the soil and undergrowth at the time of logging or by changes in forest conditions in fresh fellings, without taking into account the emerging types of clearings and forest regeneration in connection with them. In addition, there are no scientifically based acceptable limits for the preservation of undergrowth and the size of the damaged soil surface with different densities of its upper layers. This leads to difficulty in objectively assessing the performance of logging equipment and its environmental consequences. The mentioned methodological approach to substantiating the criteria for silvicultural and environmental assessment of the operation of logging equipment is based on the use of cause-and-effect relationships between the input and output parameters of forest ecosystems and inter-level connections of plant parcels and biogeocenoses using the indicator of the occurrence of undergrowth. Of particular importance for establishing criteria are input indicators (preservation of undergrowth, degree of soil mineralization, density of its upper layers), which significantly influence the output of the ecosystem - types of felling, initial and subsequent stages of forest types. In areas with mature forest, depending on the method of regeneration after logging, different requirements are imposed on technological processes. The basis for classifying forest areas before logging to certain methods of regeneration (natural, preliminary and subsequent, artificial) after logging can be the amount of occurrence of undergrowth before logging or the likelihood of the formation of types of fellings with favorable or unfavorable conditions for the regeneration of the main species. Silvicultural and environmental requirements during the operation of logging machines in stands with undergrowth are imposed mainly on the occurrence of undergrowth (its other characteristics: density, viability and others are classified as restrictions), since this indicator is a reliable criterion for assessing the natural regeneration of the forest, allowing one to predict the composition and productivity of forest stands. The acceptable preservation of undergrowth is established by the ratio of the occurrence of preserved undergrowth under the forest canopy before felling and the occurrence of preserved undergrowth, according to which forest regeneration is assessed satisfactorily. The silvicultural and environmental requirements for the operation of logging machines in cutting areas without undergrowth are different. They depend on the method of regeneration after felling, i.e. taking into account the likelihood of the formation of one or another type of clearing and the forecast of the occurrence of undergrowth.[...]
For satisfactory regeneration of pine and larch stands on poor dry soil (in heath forests, lingonberries and similar ones), the preservation of a significant amount of undergrowth, numbering in the thousands per 1 hectare, is required. To renew the spruce or spruce-fir forest stand on fresh and wet soils(in sorrel and blueberry forests) very often it is enough to preserve several hundred pieces of spruce and fir undergrowth per 1 hectare, if it is more or less evenly distributed over the area.[...]
As for ash, in its youth it is indeed more shade-tolerant than many of the species with which it grows in our forest-steppe mixed stands. Observations in these forests have shown that ash undergrowth actually often prevails over self-seeding oak and undergrowth of other species, despite the shading from above, often with three tiers (Krasnopolsky, A.V. Tyurin).[...]
Trees are felled with their tops in the direction of the movement of the fire. Branches cut off from trees are carried into the forest in the direction from which the fire is coming, and sections of cross-cut trunks are dragged in the direction opposite to the movement of the fire. Living cover, undergrowth and undergrowth are removed from the middle part of the breaking strip. The humus layer turns over, exposing the soil to the mineral layer.[...]
In place of wet blueberry spruce forest, immediately after felling, sphagnum, rush-pike and pike types of fellings are formed. The first is formed when there is damage to the soil surface on 35-40% of the cleared area and sufficiently high preservation of the undergrowth (up to 60%). This type passes into lancet-reed-sphagnum, and then into moist blueberry spruce forest. The rush-pike and pike types of clearings are formed with significant soil compaction (usually 1.3 g/cm3 or more in the upper layer) and are most often confined to places near loading areas and logging slopes. In clearings of these types, conditions for the regeneration of spruce are extremely unfavorable, and for deciduous trees (mainly downy birch) - difficult.[...]
The disadvantages of preliminary regeneration are unevenness in the width and structure of the annual layers of wood before and after felling, and the subsequent increased knottiness and curvature of the trunks. These shortcomings, especially the knotty nature, are more associated with adolescents who have experienced prolonged oppression before logging. With severe suppression of the undergrowth, the annual layers are not only narrow (from hundredths to several tenths of millimeters), but often fall out altogether, and a heeling of the trunk develops.[...]
The plots are divided into apiaries with a width equal to the average height of the tree stand, with a minimum trail width of 4 - 5 m. Development of the apiary begins from the near ends. The felted trees are placed with their tops on the drag at an acute angle to it, so they do not have to be turned when pulled out. The undergrowth is retained in the amount of 70-75% more or less evenly over the entire area of the strips. With this method, small and large undergrowth is well preserved. Working conditions made it possible to reduce the composition of small complex teams by 1 - 2 people. Labor costs for chokering and skidding over the tops in the summer are 6 - 7% higher than for choking and skidding over the butts. However, the costs are offset by savings in reducing the labor intensity of clearing cutting areas, since with this method the branches are concentrated on the drags.[...]
The first way has become more widespread. Over the past three decades, many different technological schemes for the logging process have been proposed. The ideal is still far away, but there is some progress - a number of schemes ensure the preservation of regrowth up to 60 - 70%. However, this goal is becoming less and less achievable due to the introduction of powerful logging machines, which increase the impact on the forest and forest environment. First of all, the impact of such machines as VTM-4, VM-4A, LP-49, etc., affects the soil. Its compaction, strong exposure and movement, erosion and depletion are observed, undergrowth is destroyed and damaged, and injuries are caused to the roots and trunks of trees. During clear cuttings, this can lead to the formation of types of clearings that are unfavorable for forest regeneration.[...]
Fricke fell into such a gross mistake when he came out with a categorical objection to the division of tree species into shade-tolerant and light-loving as a “scientifically unfounded dogma.” The basis for Fricke’s speech was a special experience that involved freeing undergrowth under the forest canopy from “root competition.” But this experience in itself only proves that the success of the growth and development of undergrowth depends not only on lighting conditions, but also on the conditions of soil nutrition, which in turn is a condition for air nutrition of plants.[...]
Introduction of air-suspended skidding equipment (Fig. 109), rational trays (Fig. PO), regulation of the direction of tree felling using technical devices (wedges, etc.), prohibition of clear cutting on steep slopes, transition to regulated selective and gradual felling - Here is an incomplete list of means for preserving iodrosga in mountain forests. To this we must add much that applies to lowland forests, for example, the use of snow cover to protect self-seeding and undergrowth from damage.[...]
In clearing areas, the composition and especially the number of fauna change. In the first years after logging in the spruce forests of the Arkhangelsk region, the number of squirrels decreases and disappears pine marten, birds of the Galliformes order. At the same time, the number of mouse-like rodents, stoats and foxes increases. The productivity of hunting lands, decreasing noticeably in the first years after logging, then increases as afforestation occurs and after 20 years becomes higher than the productivity of spruce forest lands. Clear cuttings are expanding the range of moose, hare and black grouse. The preserved undergrowth and the remaining seed clumps increase the hunting value of the clearings. Concentrated logging promotes the movement of the cockchafer to the north. Currently, it is widespread throughout the forest zone of the European part of the country and causes damage to crops and the natural regeneration of pine. This is due to favorable conditions for the May beetle: light and thermal conditions, penetration of the soil of clearings, the presence of herbaceous and other plants, the roots of which provide good and accessible food for young May beetle larvae. Grass cuttings (reed type) and some types of firewood are especially favorable for it.[...]
The natural regeneration of concentrated clear-cutting areas, as shown by numerous studies (Department of General Forestry of the Leningrad Tatarstan named after S. M. Kirov, Arkhangelsk Forestry Engineering Institute, Central Scientific Research Institute of Forestry, Northern Forest Experimental Group, Institute of Forest of the USSR Academy of Sciences, etc.), takes place in many areas of the taiga zone successfully, but mainly in hardwoods. In other types of forests, the participation of conifers in the regeneration of cutting areas is rare and mainly due to the undergrowth remaining after logging and the slow appearance of self-seeding pine and spruce under the canopy of deciduous trees, which usually populate the cutting area in the first years after logging.
Development of self-seeding
The young generation of woody plants up to 3-5 years old, and in northern conditions up to 10 years old, formed from seeds naturally, called self-seeding. Shoots that appear on the soil surface as a result of sowing seeds are called seedlings.
In the first year of its life, the size of self-seeding is far from the same. The height of 2-year-old seed pine varies from 2 to 14 cm, and the height of 2-year-old seed birch varies from 11 to 76 cm. Significant differences in height, diameters and other external signs self-seeding and undergrowth was explained by Charles Darwin. He explained fluctuations in growth and development primarily by individual variability. The hereditary characteristics of organisms within the same species are different.
Individual plant variability is most pronounced at a young age. For shoots or seedlings external conditions environment are grass cover, showers, snow, snowfalls and other factors. They enhance the process of differentiation. which ultimately ends in failure. Natural thinning occurs, i.e. the loss of part of the self-seeding, which lasts in the planting throughout the life of the tree stand, but occurs at a maximum at a young age.
The growth of seedlings also depends on the thickness and density of the litter. As the thickness of the forest floor increases, the total amount of self-sowing and undergrowth decreases. In forest types where the litter consists of litter from deciduous trees - ash, oak - and conifers, the development of self-seeding pine can be successful. In the presence of a dense litter of maple, aspen, linden, and elm leaves, seedlings covered with these leaves die. Mother trees in the forest create favorable conditions for the development of self-seeding, protecting, for example, tender shoots from the sun, preventing herbaceous vegetation from growing wildly.
Grass ground cover plays a negative role in the process of natural regeneration, especially reed grass, meadow grass, bluegrass, etc. Cereal plants form dense turf, preventing the emergence and development of seedlings. However, grasses and mosses do not always have a negative meaning. In the early stages of its development, sphagnum can be an additional moisturizer for downy birch seedlings.
Dense moss cushions made of cuckoo flax or sphagnum in the taiga coniferous forest prevent the successful development of self-seeding. Emerging seedlings with strong growth of moss or grasses may die due to lack of moisture. The upper soil horizons are drying out. If there is a forest under the canopy or heather is cleared, the appearance of turf grasses is excluded and favorable conditions are created for the growth and development of pine. Plants such as fireweed, heather, European hoofweed, kupena, and crow's eye help loosen the soil.
The growth of some plants in the ground cover can cause the risk of certain diseases of woody plants. So, in northern regions Taiga spruce is affected by a rust fungus that spreads from wild rosemary.
Living ground cover in cleared areas can be useful for tree seedlings, as it protects them from frost, sunburn, and the drying effects of wind. Fireweed, etc., have a protective effect on the self-seeding of conifers. However, the cover is dangerous for tree seedlings as a competitor, taking away moisture, food, light and heat from them. Some plants (for example, lupine and clover) enrich the soil with nitrogen, improving the conditions for forest development. Knowing the nature of the grass cover, you can easily prevent its negative effects on the growth of self-seeding main tree species.
Adolescence development
The young generation of woody plants under the forest canopy or in clearings, capable of forming a forest stand, is called undergrowth. The presence of a sufficient amount of undergrowth under the forest canopy or in clearing does not mean that the forest needed for the farm has been formed. There are a number of factors that directly or indirectly negatively affect the further course of forest formation. Low temperatures and frosts often damage the undergrowth, as a result of which the plants grow poorly and take on a crooked shape. On heavy, damp and damp soils, the undergrowth is squeezed out of the soil by frost. Among young teenagers there is a large number of injuries and diseases.
The closing of the crowns of the undergrowth marks a new qualitative stage in the formation of the forest. In the case of uniform distribution of undergrowth arising from seeds of one seed year, a uniform closure is formed. From this period, undergrowth is considered a plantation, and the area occupied by it is classified as covered with forest. In the case of clump placement of undergrowth, the closure of the crowns occurs later than with uniform placement. Clump regeneration is typical for multi-aged coniferous forests.
The undergrowth of individual tree species is classified taking into account their characteristics. Thus, spruce undergrowth is divided into three categories of reliability: stable, dubious and unreliable. (208;5)
The condition of the undergrowth (its growth and development under the forest canopy) depends on the closeness of the crowns of the maternal canopy. The largest amount of reliable undergrowth in coniferous forests occurs at a density of 0.4-0.6. A decrease or increase in canopy density negatively affects the reliability and abundance of young growth. In highly dense plantings, little light and heat penetrates the soil surface, there is not enough moisture in the soil, and the top layer of soil is in a supercooled state for a long time. Therefore, those seedlings that are “lucky enough” to appear here almost all die in the future. IN rare forest the other extreme. Abundance of light and heat promotes growth
turf. Under these conditions, the pine undergrowth, having acquired independent significance, cannot withstand competition with the grass cover and dies either from frost or from the sun.
Various tree species under a closed forest canopy can remain in a state of oppression for a long time. For example, spruce and fir undergrowth up to 60 years or more. Pine, birch and aspen do not tolerate prolonged shading. Undergrowth plays a positive role in forest regeneration.
Undergrowth under the forest canopy reacts to sudden lightening to varying degrees. Young coniferous trees after removal of the parent forest canopy can get burned or significantly slow down growth and accelerate development.
480 rub. | 150 UAH | $7.5 ", MOUSEOFF, FGCOLOR, "#FFFFCC",BGCOLOR, "#393939");" onMouseOut="return nd();"> Dissertation - 480 RUR, delivery 10 minutes, around the clock, seven days a week and holidays
Gutal Marko Milivojevic. Viability and structure of spruce undergrowth under the canopy of tree stands and in clearings: dissertation... Candidate of Agricultural Sciences: 06.03.02 / Gutal Marko Milivoevich;[Place of defense: St. Petersburg State Forestry University named after S.M. Kirov http://spbftu.ru/science/sovet/D21222002/dis02/].- St. Petersburg, 2015.- 180 p.
Introduction
1 Problem status 9
1.1 General information about spruce phytocenoses 9
1.2 Spruce juvenile 11
1.2.1 Features of the age structure of spruce undergrowth 12
1.2.2 Features of the light regime under the canopy of spruce forests 16
1.2.3 Viability of spruce undergrowth 22
1.2.4 Number of spruce undergrowth 25
1.2.5 Influence of forest type on spruce regrowth 27
1.2.6 Features of the development of spruce undergrowth under the canopy 30
1.2.7 Influence of vegetation of lower tiers on spruce regrowth 33
1.2.8 The influence of economic activities on spruce juveniles 35
2 Research program and methodology 39
2.1 Research program 39
2.2 Study of forest phytocenosis by structural elements 40
2.2.1 Determination of the main characteristics of the forest stand 40
2.2.2 Accounting for teenagers 41
2.2.3 Accounting for undergrowth and living ground cover 46
2.2.4 Determination of biometric indicators of needles 49
2.3 Research objects 51
2.4 Scope of work performed 51
3 Dynamics of the state of spruce undergrowth under the canopy .
3.1 Dynamics of the vital state of spruce undergrowth based on the results of long-term studies 53
3.2 Patterns of changes in the viability of spruce undergrowth in connection with the type of forest 69
3.3 Influence of the maternal canopy on the dynamics of the state and structure of spruce undergrowth
3.4 Relationship between the viability of spruce undergrowth and the value of average growth over a period of 3, 5 and 10 years.
3.5 Age structure as an indicator of the state of adolescence 86
3.6 Structure according to the height of undergrowth as an indicator of condition 89
3.7 Comparative analysis of the state and structure of spruce undergrowth in the spruce forests of the Lisinsky and Kartashevsky forestries 93
4 The influence of economic activities on the number and viability of spruce undergrowth
4.1 The influence of thinning on the dynamics of viability of spruce undergrowth 105
4.2 Thinning the undergrowth - as a measure to promote the natural regeneration of spruce 122
5 Dynamics of the condition of spruce undergrowth in the felling area 127
5.1 Features of the structure and condition of spruce undergrowth 127
5.2 Dependence of the dynamics of the state of spruce undergrowth on the recency of felling 134
6 Biometric characteristics of needles as an indicator of the viability of spruce undergrowth
6.1 Biometric indicators of needles under the canopy and in cuttings 140
6.2 Biometric indicators of needles of viable and non-viable spruce undergrowth.
References
Features of the light regime under the canopy of spruce forests
Spruce is one of the main forest-forming species in the Russian Federation, occupying fourth place in terms of area, second only to larch, pine and birch. Spruce grows from the tundra to the forest-steppe, but it is in the taiga zone in the most to a greater extent its forest-forming and edificatory role is manifested. The genus spruce (Picea Dietr.) belongs to the pine family (Pinacea Lindl.). Individual representatives of the spruce genus date back to the Cretaceous period, that is, 100-120 million years ago, when they had one common habitat on the Eurasian continent (Pravdin, 1975).
Norway spruce or common spruce (Picea abies (L.) Karst.) is widespread in northeastern Europe, where it forms continuous forests. In Western Europe coniferous forests are not a zonal type of vegetation, and vertical differentiation takes place there. The northern border of the range in Russia coincides with the forest border, and the southern border reaches the black earth zone.
Norway spruce is a tree of the first size with a straight trunk, a cone-shaped crown and not strictly whorled branching. The maximum height reaches 35-40 meters in flat conditions, and in the mountains there are specimens up to 50 m high. The oldest known tree was 468 years old. However, age over 300 years is very rare, and in the zone of coniferous-deciduous forests it decreases to 120-150 (180) years (Kazimirov, 1983).
Norway spruce is characterized by relatively high plasticity of the root system, capable of adapting to various soil conditions. The root system is most often superficial, but on well-drained soils relatively deep vertical branches often develop (Shubin, 1973). The trunk of the Norway spruce is full wood, covered with relatively thin green-brown, brown or gray bark. The bark of the common spruce is smooth, but with age it becomes scaly and furrowed.
Growth buds are small - from 4 to 6 millimeters, ovoid-conical, red with dry scales. Reproductive buds are larger and reach 7-10 millimeters.
The needles of the common spruce are tetrahedral, sharp, dark green, hard, shiny, up to 10-30 mm long and 1-2 millimeters thick. It stays on shoots for 5-10 years and falls off throughout the year, but most intensively from October to May.
Norway spruce blooms in May–June. The cones ripen in the fall the next year after flowering, the seeds fall out at the end of winter and early spring next year. Male spikelets of elongated cylindrical shape are located on the shoots of the previous year. The cones are spindle-shaped, cylindrical, 6 to 16 cm long and 2.5 to 4 centimeters in diameter, located at the ends of the branches. Young cones are light green, dark purple or pinkish, while mature ones take on a different shade of light brown or red-brown. Mature cones contain from 100 to 200 seed scales on the stem. Seed scales are lignified, obovate, entire, finely serrated along the upper edge, notched. Each seed scale contains 2 seed cavities (Kazimirov, 1983). The seeds of the common spruce are brown in color, relatively small, 3 to 5 millimeters long. Weight of 1000 seeds is from 3 to 9 grams. Seed germination varies from 30 to 85 percent depending on growing conditions. Growing conditions also determine the presence of repetition of productive years, which occur on average every 4-8 years.
Norway spruce is a species that grows over a relatively large area, in different soil and climatic conditions. As a result, Norway spruce is distinguished by high intraspecific polymorphism (in the type of branching, color of cones, crown structure, phenology, etc.), and therefore by the presence of a large number of ecotypes. In relation to air temperature, the common spruce is thermophilic, but at the same time it is a cold-resistant species, growing in a zone of temperate and cool climates with an average annual temperature of -2.9 to +7.4 degrees and the temperature of the warmest month of the year from +10 to +20 degrees (Chertovskoy, 1978). The distribution range of Norway spruce ranges from 370 to 1600 mm of precipitation per year.
The issue of soil moisture is closely related to its aeration. Although common spruce is capable of growing in conditions of excess moisture, good productivity should be expected only in cases where there is running water. On damp soils, spruce falls out at a speed of 6-7 meters per second, and on fresh and dry soils it can withstand wind flows at a speed of 15 meters per second. Wind speeds of more than 20 meters per second cause a massive fall.
The most intensive growth of common spruce occurs on sandy and loamy soils, underlain at a depth of 1-1.5 meters by clays or loams. It should be noted that there are no strict rules for the requirements for soil composition and mechanical composition as such, since the requirements of spruce for soil are of a zonal nature. Norway spruce has a high tolerance threshold to soil acidity and is able to grow at pH fluctuations from 3.5 to 7.0. Norway spruce is relatively demanding in terms of mineral nutrition (Kazimirov, 1983).
Accounting for undergrowth and living ground cover
Heterogeneity of qualitative and quantitative characteristics adolescence is expressed, first of all, through the concept of the viability of adolescence. The viability of adolescents according to the Encyclopedia of Forestry (2006) is the ability of the younger generation of maternal adolescents to exist and function in changing environmental conditions.
Many researchers, such as I.I. Gusev (1998), M.V. Nikonov (2001), V.V. Goroshkov (2003), V.A. Alekseev (2004), V.A. Alexeyev (1997) and others noted that the study of the qualitative parameters of spruce forests, by and large, comes down to studying the condition of the stands.
The state of the tree stand is a consequence of the complex processes and stages through which the plant passes from its primordium and seed formation to its transition to the dominant tier. This long process of plant metamorphosis requires division into various stages, each of which must be studied in a separate order.
Thus, it can be stated that relatively little attention is paid to the concept of vitality and state of the undergrowth (Pisarenko, 1977; Alekseev, 1978; Kalinin, 1985; Pugachevsky, 1992; Gryazkin, 2000, 2001; Grigoriev, 2008).
Most researchers claim that there is a sufficient amount of viable spruce undergrowth under the canopy of mature forest stands, but most often the interdependence of the state of the undergrowth and its spatial distribution with the characteristics of the maternal tree stand is not revealed.
There are also researchers who do not claim that under the canopy of the maternal tree stand there should be viable undergrowth capable of fully replacing the mother tree stand in the future (Pisarenko, 1977; Alekseev, 1978; Pugachevsky, 1992).
Fluctuations in height and group distribution of spruce undergrowth allowed some authors to argue that spruce undergrowth as a whole is not capable of providing preliminary regeneration under the condition of intensive logging operations (Moilanen, 2000).
Another study by Vargas de Bedemar (1846) established that the number of trunks sharply decreases with age, and that of the sprouted seedlings, in the process of natural selection and differentiation, only about 5 percent are preserved to the age of ripeness.
The process of differentiation is most pronounced in the “youth” of the planting, where the oppressed classes are distinguished to the greatest extent by status, and gradually takes over the “old age”. According to G.F. Morozov, who refers to earlier works by Ya.S. Medvedev (1910) in this direction, common feature the undergrowth growing in the plantation is oppressed. Evidence of this is the fact that at the age of 60-80 years, spruce undergrowth under a canopy very often does not exceed 1-1.5 m, while spruce undergrowth in the wild at the same age reaches a height of 10-15 meters.
However, G.F. Morozov (1904) notes that the productivity and productivity of individual specimens of undergrowth can change for the better, as soon as the environmental conditions change. All specimens of undergrowth, of varying degrees of depression, differ from undergrowth in the wild in the morphological characteristics of the vegetative organs, incl. fewer buds, a different crown shape, a poorly developed root system, and so on. Such morphological changes in spruce, such as the formation of an umbrella-shaped crown developing in a horizontal direction, are an adaptation of the plant to the most efficient use of the “scarce” light penetrating to the undergrowth. Studying cross-sections of the stems of spruce undergrowth growing in the conditions of the Leningrad District (Okhtinskaya Dacha), G.F. Morozov noted that in some specimens the annual layers were densely closed at the initial stage of life (which indicates the degree of oppression of the plant), and then sharply expanded as a result of certain forestry measures (in particular thinning), changing environmental conditions.
The spruce youngsters, abruptly finding themselves in open space, also die from excessive physiological evaporation due to the fact that in open areas this process occurs with greater activity, to which the youngsters growing under the canopy are not adapted. Most often, this teenager dies as a result of a sharp change in the situation, but, as G. F. Morozov noted, in some cases, after a long struggle, he begins to recover and survives. The ability of a young plant to survive in such circumstances is determined by a number of factors, such as the degree of its oppression, the degree of severity of changes in environmental conditions, and, of course, biotic and abiotic factors affecting the growth and development of the plant.
Individual specimens of undergrowth often vary greatly within the same massif in such a way that one specimen of undergrowth, marked before felling as nonviable, recovered, while another remained in the category of nonviable. Spruce regrowth, formed on fertile soils under the canopy of birch or pine, often does not respond to the removal of the upper tier, because did not experience light deficiency even in its presence (Cajander, 1934, Vaartaja, 1952). After a buffer period of adaptation, the height growth of undergrowth increases many times, but small undergrowth requires more time for the functional restructuring of vegetative organs (Koistinen and Valkonen, 1993).
Indirect confirmation of the fact of the expressed ability of the spruce undergrowth to change the category of condition for the better was given by P. Mikola (1966), noting that a significant part of the rejected spruce forests (based on the state of the undergrowth), in the process of forest inventory in Finland, was later recognized as suitable for forest growing.
Age structure as an indicator of the state of adolescence
Depending on the structure of the planting, from 3 to 17 percent of photosynthetic active radiation can penetrate under the canopy of spruce forests. It should also be noted that as edaphic conditions worsen, the degree of absorption of this radiation decreases (Alekseev, 1975).
The average illumination in the lower tiers of spruce forests in blueberry forest types most often does not exceed 10%, and this, in turn, on average provides the minimum energy for annual growth, which ranges from 4 to 8 cm (Chertovskoy, 1978).
Research in the Leningrad region, conducted under the direction of A.V. Gryazkina (2001) show that the relative illumination on the soil surface under the canopy of tree stands is 0.3-2.1% of the total, and this is not enough for the successful growth and development of the young generation of spruce. These experimental studies showed that the annual growth of the young generation of spruce increases from 5 to 25 cm with an increase in light penetrating under the canopy from 10 to 40%.
Viable spruce undergrowth in the overwhelming majority of cases grows only in the windows of the canopy of a spruce stand, since in the windows the spruce undergrowth does not experience a lack of light, and besides, the intensity of root competition there is much lower than in the near-trunk part of the stand (Melekhov, 1972).
V.N. Sukachev (1953) argued that the death of undergrowth is largely determined by root competition of mother trees, and only then by light deficiency. He supported this statement by the fact that in the very early stages of a teenager’s life (the first 2 years) “there is a strong decline of spruce regardless of the light.” Authors such as E.V. Maksimov (1971), V.G. Chertovsky (1978), A.V. Gryazkin (2001), K.S. Bobkova (2009) and others question such assumptions.
According to E.V. Maksimov (1971), undergrowth becomes unviable when illumination is from 4 to 8% of full. Viable undergrowth is formed in the gaps between the crowns of mature trees, where illumination averages 8-20%, and is characterized by light needles and a well-developed root system. In other words, viable undergrowth is confined to gaps in the canopy, and strongly suppressed undergrowth is located in the zone of dense closure of the upper tiers (Bobkova, 2009).
V.G. Chertovskoy (1978) also claims that light has a decisive influence on the viability of spruce. According to his arguments, in medium-density stands, viable spruce regrowth usually accounts for more than 50-60% of the total. In tightly closed spruce forests, nonviable undergrowth predominates.
Research in the Leningrad region showed that the lighting regime, i.e. The canopy closeness determines the proportion of viable undergrowth. When the canopy density is 0.5-0.6, undergrowth with a height of more than 1 m predominates. In this case, the proportion of viable undergrowth exceeds 80%. When the density is 0.9 or more (relative illumination less than 10%), viable undergrowth is most often absent (Gryazkin, 2001).
However, other environmental factors should not be underestimated, such as soil structure, soil moisture, and temperature regime(Rysin, 1970; Pugachevsky, 1983, Haners, 2002).
Although spruce is a shade-tolerant species, spruce undergrowth in high-density plantings still experiences great difficulties in low light conditions. As a result, the quality characteristics of undergrowth in dense plantations are noticeably worse compared to undergrowth growing in medium-density and low-density plantations (Vyalykh, 1988).
As the spruce tree grows and develops, the threshold of tolerance to low light decreases. Already at the age of nine years, the need for light in spruce trees increases sharply (Afanasyev, 1962).
The size, age and condition of the undergrowth depend on the density of forest stands. Most mature and overmature coniferous plantations are characterized by different ages (Pugachevsky, 1992). The largest number of juvenile specimens is found at a density of 0.6-0.7 (Atrokhin, 1985, Kasimov, 1967). These data are confirmed by the research of A.V. Gryazkina (2001), who showed that “ optimal conditions to form viable undergrowth with a population of 3-5 thousand individuals/ha, they are formed under the canopy of tree stands with a density of 0.6-0.7”.
NOT. Dekatov (1931) argued that the main prerequisite for the appearance of viable spruce regrowth in the sorrel forest type is that the completeness of the maternal canopy is in the range of 0.3-0.6.
Viability, and therefore growth in height, is largely determined by the density of the planting, as evidenced by the research of A.V. Gryazkina (2001). According to these studies, the increase in non-viable undergrowth in sorrel spruce forests with a relative stand density of 0.6 is the same as the increase in viable undergrowth when the sorrel spruce forest density is 0.7-0.8.
In blueberry-type spruce forests, with increasing stand density, the average height of undergrowth decreases and this dependence is close to a linear relationship (Gryazkin, 2001).
Research by N.I. Kazimirova (1983) showed that in lichen spruce forests with a density of 0.3-0.5, spruce undergrowth is rare and qualitatively unsatisfactory. The situation is completely different with sorrel forests, and especially with lingonberry and blueberry forest types, where, despite the high density, there is a sufficient amount of undergrowth that is satisfactory in terms of vital condition.
Dependence of the dynamics of the state of spruce undergrowth on the recency of felling
As the relative density of the tree stand increases, the proportion of medium and large viable spruce undergrowth also increases, since competition for light in such a closed canopy most affects the small undergrowth. With a high stand density, the proportion of non-viable small spruce undergrowth is also very large. However, this proportion is significantly larger when the relative density is low, since in such light conditions competition increases, from which small juveniles primarily suffer.
With an increase in the relative density of the forest stand, the share of small non-viable undergrowth changes as follows: at low density, the share of small non-viable undergrowth is the largest, then it falls and reaches a minimum at a density of 0.7, and then increases again with increasing density (Figure 3.40).
The distribution of spruce undergrowth by condition and size categories confirms that the life potential of undergrowth grown in the conditions of the Lisinsky forestry is greater than that of spruce undergrowth in the Kartashevsky forestry. This is especially clearly seen in the altitudinal structure of the undergrowth, since the proportion of medium and large spruce undergrowth is, as a rule, greater at the Lisisinsky sites under similar forest conditions (Figures 3.39-3.40).
The better life potential of spruce undergrowth at the Lisinsky sites is also evidenced by the growth rates of undergrowth, which are shown in Figures 3.41-42. For each age group, regardless of life status, the average height of spruce undergrowth at the Lisinsky sites is greater than the average height of undergrowth grown in the conditions of the Kartashevskoye forestry. This once again confirms the thesis that in relatively less favorable conditions environment (from the point of view of soil moisture and its fertility - closer to the blueberry forest type), spruce youngsters are more able to demonstrate their competitive abilities. It follows that changes occurring in the canopy as a result of anthropogenic or other impacts give a more positive result in the context of improving the condition of spruce undergrowth in the conditions of Lisinsky rather than Kartashevsky forestry.
1. At each stage of development, the number of undergrowth, as well as the structure in height and age in the experimental plots, change in different directions. However, a certain pattern has been identified: the more the number of undergrowth changes (after productive seed years it increases sharply), the more the structure of undergrowth changes in height and age. If, with an increase in the number of undergrowth due to self-seeding, a significant decrease in the average height and average age occurs, then with a decrease in the number as a result of mortality, the average height and average age can increase - if predominantly small undergrowth goes into decline, or decrease - if mainly large undergrowth goes into decline teenager
2. Over 30 years, the number of undergrowth under the canopy of the sorrel spruce and blueberry spruce forests has changed; in this component of the phytocenosis, the change of generations is continuous - the main part of the older generation goes into decline, and the undergrowth of new generations regularly appears and, first of all, after bountiful harvest seeds
3. Over three decades, the composition of undergrowth at the observation sites has changed significantly, the share of deciduous trees has increased markedly and reached 31-43% (after cutting). At the beginning of the experiment it did not exceed 10%.
4. In section A of the ecological station, the number of spruce undergrowth increased by 2353 specimens over 30 years, and taking into account the surviving model specimens, the total number of spruce undergrowth by 2013 was 2921 specimens/ha. In 1983 there were a total of 3049 specimens/ha.
5. Over three decades, under the canopy of the blueberry spruce and sorrel spruce forests, the share of undergrowth that moved from the “nonviable” category to the “viable” category was 9% in section A, 11% in section B and 8% in section C, i.e. on average about 10%. Based on the total number of undergrowth on the experimental plot of 3-4 thousand/ha, this proportion is significant and deserves attention when carrying out accounting work when assessing the success of natural regeneration of spruce in the indicated forest types. 103 6. From the “viable” category to the “non-viable” category over the specified period of time, from 19 to 24% moved from the “viable” category to the “dry” category (bypassing the “non-viable” category) – from 7 to 11%. 7. Of the total number of growing undergrowth in section A (1613 specimens), 1150 undergrowth specimens were lost different heights and different ages, i.e. about 72%. In section B – 60%, and in section C – 61%. 8. During observations, the proportion of dry undergrowth increased with increasing height and age of the model specimens. If in 1983-1989. it amounted to 6.3-8.0% of the total, then by 2013 dry undergrowth already accounted for from 15 (blueberry spruce forest) to 18-19% (sorrel spruce forest). 9. Of the total number of certified undergrowth in section A, 127 specimens became trees of reduced size, i.e. 7.3%. Of these, the majority (4.1%) are those specimens that were transferred to different years from the “non-viable” category to the “viable” category. 10. Repeated recording of the same specimens of spruce undergrowth over a long period of time makes it possible to indicate the main reasons for transitions from the “non-viable” category to the “viable” category. 11. Changes in the structure of undergrowth in height and age, fluctuations in numbers are a dynamic process in which two mutually opposite processes are simultaneously combined: the decline and arrival of new generations of undergrowth. 12. Transitions of adolescents from one category of condition to another, as a rule, occur more often among small adolescents. The younger the teenager is, the more likely a positive transition is. If during the first 6 years of observation, about 3% of specimens moved from the “VF” category to the “F” category. (with the average age of a teenager being 19 years), then after 20 years - less than 1%, and after 30 years - only 0.2%. 13. The dynamics of the state of undergrowth is also expressed by forest type. The transition of non-viable undergrowth to the “viable” category is more likely in the blueberry spruce forest than in the sorrel spruce forest.
Municipal educational institution
Oktyabrskaya secondary school
Manturovo municipal district
Kostroma region
Spruce forest and its undergrowth
Completed:
Borodinsky Ilya Pavlovich
8th grade student
Municipal educational institution Oktyabrskaya secondary school
Supervisor:
Smirnova Tatyana Valerievna
1. Introduction. 3
2. Research methodology. 4 3.Results of the study.
3.1. Features of the spruce forest. 5
3.2. Species composition of spruce forest. 7
3.3. Young spruce forest. 8
3.4. The influence of mature trees on the growth of spruce seedlings and spruce undergrowth. 8
3.5. The influence of mature trees on the formation of young trees. 9
4. Conclusions. 11
5. Conclusion and prospects 12 6. List of references. 13 7. Applications. 14
1.Introduction
Most of our area is occupied by spruce forests. Spruce forest is completely special, unique plant community. This forest is gloomy, shady, damp. If you enter a spruce forest from a field or meadow on a hot summer day, you will immediately find yourself in deep shade and feel cool and damp. The whole situation here is sharply different from what is typical of an open place. Spruce changes a lot environment, creates specific conditions under its canopy.
The composition of plants in the lower layers of the forest is largely determined by the properties of the soil. In those parts of the spruce forest where the soil is poorer in nutrients and more moist, we usually find dense thickets of blueberries on the moss carpet. This type of forest, found near the village of Oktyabrsky, is called a spruce-blueberry forest.
Purpose of the work:
study the spruce forest and the undergrowth of the spruce forest.
Tasks:
Find out the features of the spruce forest;
Study the species composition of the spruce forest;
Study the undergrowth of the spruce forest;
Conduct research and identify the influence of mature trees on the growth of spruce seedlings and spruce undergrowth;
Identify the influence of mature trees on the formation of undergrowth.
2. Research methodology
We conducted research work in the summer of 2011.
For our research we used the following equipment: pegs, measuring fork, tape measure.
When performing this work, we used observation and comparison methods. Using the observation method, the species composition of the spruce forest, the external features of the undergrowth and the spruce forest seedlings were studied. The tables were compiled based on the comparison method. This method made it possible to consider and compare the number of sprout sprouts and regrowth, and also helped to determine the final results in this work.
As a result of the analysis of literary sources on biology and ecology, we became acquainted in detail with the vegetation of the spruce forest, soils, growing conditions,,,
3.Research results
3.1. Features of the spruce forest
The spruce forest is a completely special, unique plant community (Appendix I photo1). Spruce creates very strong shading, and only fairly shade-tolerant plants can exist under its canopy. There are usually few shrubs in a spruce forest. The plants that we see under the canopy of the spruce forest are quite shade-tolerant; they not only grow normally in deep shade, but even bloom and bear fruit. All these plants also tolerate the relative poverty of the soil in nutrients and its high acidity (such properties are characteristic of the soil of a spruce forest). At the same time, many spruce forest plants are demanding of soil moisture.
There is almost never any strong air movement under the canopy of the spruce forest. And in the spruce forest you will hardly find plants whose seeds would have any “parachutes” or other devices for dispersal by wind. But there are many plants whose seeds are extremely small, look like dust and are spread even by very weak air currents.
Among the plants found in spruce forests, there are many that have white flowers.
This coloring of flowers is not accidental. This is an adaptation to the poor lighting under the canopy of a spruce forest. White flowers are more visible in the twilight than any other, and are easiest for pollinating insects to find.
Almost all herbaceous plants in the spruce forest are perennial. Every spring they continue their life, but do not start it all over again, from a seed, like annual grasses. They occupy their specific place in the forest for many years. Most plants in the spruce forest have more or less long creeping rhizomes or above-ground shoots that can quickly grow laterally and take over a new area. All these are adaptations to the specific environment under the canopy of the spruce forest. The emergence of new plants from seeds here is fraught with great difficulties: the germination of fallen seeds is hampered by a thick layer of dead needles on the soil and a moss cover. Reproduction by seeds under these conditions is very unreliable. The inhabitants of the spruce forest maintain their existence mainly through vegetative reproduction. Shoots of any plants can appear from seeds only in special conditions - where the layer is removed
fallen pine needles along with the moss cover and the soil was exposed. These are the conditions that are necessary for the mass emergence of even spruce sprouts.
The litter in the spruce forest has a highly acidic pH and is decomposed almost exclusively by microscopic fungi. The fungal population is very abundant not only in the litter, but also in upper layers soil. It is not surprising, therefore, that many plants of the spruce forest have mycorrhizae; their roots are braided with a thick cover of the finest fungal threads - hyphae. Mycorrhiza plays an important role in the life of forest plants, helping them to absorb hard-to-reach materials from the soil. nutrients. Some herbs of the spruce forest are so closely associated in their life with the mycorrhizal fungus that even their seeds cannot germinate without the participation of the fungus.
Another characteristic feature of spruce forest plants is that many of them remain green for the winter and retain living foliage during the cold season. In the spring, as soon as the snow melts, you can always see their old, overwintered green leaves on the soil. If it gets a little warmer, the process of photosynthesis immediately begins in the leaves and organic substances are produced. Relatively few grasses of the spruce forest completely lose their above-ground parts in the fall and overwinter only in the form of underground organs.
Shrubs play an important role in the living ground cover of a spruce forest. All these plants do not differ from shrubs in their structural features, but are only significantly smaller in size.
The mosses that we see on the soil in the spruce forest are very shade-tolerant plants. They can exist in fairly low light. They also tolerate the mechanical impact of dry needles falling from trees. There is no moss cover only in very dense young spruce stands, where almost no light reaches the soil. Appearance The spruce forest changes little throughout the year. Spruce remains green all the time, and so do many forest herbs. The moss cover also retains its constant green color. Only in spring and early summer do we see some diversity, when some of the grasses along the canopy of the spruce forest begin to bloom.
3. 2. Species composition of the spruce forest
In a spruce forest, the main species is common spruce or Norway spruce (Appendix I photo 2). The root system is taproot for the first 10-15 years, then superficial (the main root dies). The tree is slightly wind resistant. The crown is cone-shaped or pyramidal. The branches are whorled, horizontally spread or drooping. In the first 3-4 years it does not produce lateral shoots. The bark is gray and peels off in thin sheets. The leaves are needle-shaped (needles), green, short, tetrahedral, less often flat, hard and sharp, with 2 keels on the upper and lower sides. Arranged spirally, singly, sitting on leaf pads. They remain on shoots for several (6 or more) years. Up to one-seventh of the needles fall annually. After severe eating of the needles by some insects, for example, the nun butterfly, brush shoots appear - with very short and stiff needles, reminiscent of brushes in appearance.
Gymnosperm plants. The cones are oblong-cylindrical, pointed, do not crumble, and fall off whole when the seeds ripen in the first year of fertilization. Mature cones are hanging, dry, leathery or woody, up to 15 cm long, 3-4 cm in diameter. The cones consist of an axis on which numerous covering scales are located, and in their axils there are seed scales, on the upper surface of which 2 ovules usually develop , equipped with a so-called false wing.
The seeds ripen in October and are dispersed by the wind. They do not lose germination for 8-10 years.
The beginning of fruiting is from 10 to 60 years (depending on growing conditions).
Lives on average up to 250-300 years (sometimes up to 600)
Pure spruce forests are very dense, dense, and dark. Common birch is found near spruce trees, but very rarely. There is almost no underbrush in the spruce forests, only sporadic common juniper and mountain ash are found. The herbaceous-shrub layer is well developed. Blueberries form a continuous well-developed layer. Sometimes mixed with it in significant quantities are common lingonberry, bifolia bifolia, common sorrel, horsetail, and male shield. The moss cover of blueberry spruce forests is sparse and consists of patches of sphagnum moss and cuckoo flax. After felling, in the places of former blueberry spruce forests, reed grass, pike or fireweed fellings appear, then birch, aspen and blueberry-broadgrass pine forests.
Having studied the species composition of the spruce forest, the data was entered into a description form (Appendix II)
8
3.3. Spruce forest undergrowth
Undergrowth - a young generation consisting of woody plants of natural origin growing under the forest canopy, capable of forming the main canopy of a tree stand, not reaching the height of the main tree stand
Undergrowth under the dense canopy of a mature forest has a difficult existence. Seedlings that find themselves on the edge, in a clearing, in areas where enough light penetrates into the gaps in the crowns formed after the old tree fell out, grow well. In such plants, the branches start from the very ground, they are densely covered with foliage or needles of a bright green color, their apex is well developed.
Under the canopy of the spruce forest there are many young spruce trees that did not find themselves in such favorable conditions, and they are forced to be content with what they got. And they got very little. Typically, the undergrowth grows in groups and is concentrated in conditions favorable for seed germination and the initial period of seedling growth. But as they grow, rivalry begins within the group of undergrowth; in addition, the trees are shaded by the upper canopy of the mature forest, and they have to be content with the remnants of the light that penetrated through the crowns of the trees of the older generation. The roots of the undergrowth develop in soil already occupied by the root system of the old forest, and they have to limit themselves to less food and moisture. You can often see one-meter-long fir trees in such undergrowth in a dense spruce forest, which are 30-50 years old.
In depressed undergrowth, the apical shoot is almost invisible; the branches are located only in the upper part of the stem and are located horizontally - this way more light reaches them.
IN natural forest Over the years, old trees become decrepit, gradually fall out at different times and gaps between the trees increase. More light, more moisture in the forest - less competition between the younger generation and the root system of the mother forest. The juvenile recovers, adapts to new conditions and accelerates growth, wedging its apex into the upper canopy. Even after 80-100 years of oppression, spruce can recover and become part of the upper canopy.
The undergrowth can be of seed or vegetative origin. Regrowth of seed origin at an early stage is called self-seeding (for coniferous and deciduous species with heavy seeds) or bloom (for birch, aspen and other deciduous species with light seeds). Plants up to 1 year old are considered to be seedlings. One of important means forest restoration is the preservation of undergrowth from damage during logging. 3.4. The influence of mature trees on the growth of spruce seedlings and spruce undergrowth
We chose an area of mature spruce forest (away from roads) with well-defined dead spots under the crowns of mature trees and with a moss carpet between them. We found a spruce tree, under the crown of which there is large number young seedlings (Appendix III photo1), and 5 areas measuring 100 cm 2 (10 * 10 cm 2) were laid here. Another series of platforms were placed between the treetops on a thick moss carpet. We counted the number of spruce seedlings on each plot, and then calculated the average data per plot. The results were entered into the table (Appendix III table 1)
In the same areas (i.e. under the crowns of spruce trees and between them) lay larger areas - 1 m 2 and count the amount of undergrowth present on them (Appendix IV photo1), without seedlings. The data was entered into the table (Appendix IV table 1)
We compared the results and made conclusion:
spruce shoots appear in more per unit area directly under the crowns of mature trees, since a thick layer of moss prevents their appearance between the crowns; The seedlings die before their roots reach the soil. On the contrary, the largest number of grown Christmas trees are located between the tree crowns. This discrepancy in the places where trees of different ages are abundantly found is due to the influence of mature trees. Under the crowns, due to strong competition (primarily for light), all seedlings quickly die. In the intercrown areas of the forest, the influence of mature trees is weakened, and here the majority, even of the total small number, of the emerging fir trees are preserved.
3.5. The influence of mature trees on the formation of young trees.
During the research, the state of spruce undergrowth in the forest and at the forest edge was described in order to identify the influence of adult plants on the formation of undergrowth. The undergrowth is of medium height, medium density, uneven, viable.
We chose young fir trees of approximately the same height - 1-1.5 m, growing in the shade of the forest, on its edge or in a clearing; their external structure was studied and the data was entered into a table (Appendix V table 1).
Done conclusion:
On the edges and clearings the condition of the undergrowth spruce forest is good. Here the crowns of the fir trees are cone-shaped, with densely spaced, well-covered branches. Under the forest canopy, the crowns of the fir trees are umbrella-shaped, with sparse and weakly covered branches that are strongly elongated to the sides. Moreover, in the bright areas of the forest, undergrowth grows densely, and in the shade, fir trees are found sporadically and rarely. These differences in condition and abundance
10
regrowth in different parts of the forest indicate the adverse influence of mature trees, which occurs through changes in habitat conditions: shading, etc.
From a comparison of the results, it is clear that the influence of mature spruce trees also affects the undergrowth growing between their crowns, but here it is weakened compared to the sub-crown areas; This influence has even less effect on young people who grow up at the edge of the forest.
Conclusions
As a result of the work done, we learned much more about the spruce forest, its species composition, and also studied the influence of mature trees on the growth of spruce seedlings and undergrowth, as well as on the formation of undergrowth.
After the research we came to the conclusion
There is no great species diversity in spruce forests, and only shade-tolerant plants grow.
Spruce seedlings appear in greater numbers per unit area directly under the crowns of mature trees, since a thick layer of moss prevents their appearance between the crowns; The seedlings die before their roots reach the soil. On the contrary, the largest number of grown Christmas trees are located between the tree crowns. This discrepancy in the places where trees of different ages are abundantly found is due to the influence of mature trees. Under the crowns, due to strong competition (primarily for light), all seedlings quickly die. In the intercrown areas of the forest, the influence of mature trees is weakened, and here the majority, even of the total small number, of the emerging fir trees are preserved.
At the edges and clearings the condition of the undergrowth spruce forest is good. Here the crowns of the Christmas trees are cone-shaped, with densely spaced, well-covered branches. Under the forest canopy, the crowns of the fir trees are umbrella-shaped, with sparse and weakly covered branches that are strongly elongated to the sides. Moreover, in the bright areas of the forest, undergrowth grows densely, and in the shade, fir trees are found sporadically and rarely. These differences in the condition and abundance of undergrowth in different parts of the forest indicate the unfavorable influence of mature trees, which occurs through changes in habitat conditions: shading, etc.
Conclusion
In our area there are coniferous forests and the predominant species in these forests is spruce. Every year the number of forest plantations is reduced as a result of logging and unauthorized logging.
Undergrowth is a young generation capable of forming the main forest stand. It is the main replacement of a dead or cut down forest, so we must study and protect it.
In the future, I want to continue my work on studying the spruce forest stand, as well as other tree crops.
List of used literature
1. Biological encyclopedic dictionary. Ch. ed. M. S. Gilyarov and others - 2nd edition corrected. - M.: Sov. Encyclopedia, 1989
2. Lerner G.I. Dictionary-reference book for schoolchildren, applicants and teachers. – M.: “5 for knowledge”, 2006.
3. Litvinova L.S. Moral and environmental education of schoolchildren. - M.: “5 for knowledge”, 2005.
4. Rozanov L.L. Dictionary-reference book. - M.: NTSENAS, 2002.
Appendix I
Photo 1. Spruce forest
Photo 2. Norway spruce
Appendix ΙI
Spruce forest vegetation
Description July 15, 2010Name of associations: spruce forest - blueberry
General character of the relief: flat
Soil (name): sod-podzolic loamy
Humidification conditions: not uniform
Dead litter (composition, thickness, degree of coverage, nature of distribution): last year's needles, continuous covering, evenly distributed, 2 cm
Species composition of tree species
Species composition of undergrowth
Species composition of the shrub layer
Species composition of the herbaceous-shrub layer
|
№ p/p |
View |
Latin name |
|
1. |
Blueberry |
Vaccinium myrtillus |
|
2. |
May lily of the valley |
Convallaria majalis |
|
3. |
Maynik two-leaf |
Mojanthenum bifolium |
|
4. |
Common lingonberry |
Vaccinium vitisidaea |
|
5. |
Common oxalis |
Oxalis acetosella |
|
6. |
Male shieldweed |
Dryopteris filix-mas |
Appendix II
Photo 1. Spruce shoots
|
Growing conditions |
Number of spruce shoots |
|||||
|
|
Averages |
|||||
|
1 |
2 |
3 |
4 |
5 | ||
|
Under the treetops |
4 |
10 |
3 |
5 |
5 |
5,4 |
|
Between crowns (on a layer of moss) |
2 |
4 |
7 |
4 |
1 |
3.6 |
Table 1. Number of spruce shoots
Appendix ΙV
Photo 1. Young spruce
|
Growing conditions |
Number of spruce regrowth |
|||||
|
On separate accounting sites |
Averages |
|||||
|
1 |
2 |
3 |
4 |
5 | ||
|
Under the treetops |
1 |
1 |
1 |
1 |
1 |
1 |
|
Between crowns (on a layer of moss) |
2 |
2 |
3 |
1 |
2 |
2 |
Table 1. Amount of spruce undergrowth
Appendix V
Table 1. Condition of spruce undergrowth in different conditions
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